By the numbers: Auckland’s Sky Tower turns 25
Auckland’s best-known landmark, the Sky Tower, celebrated its 25th birthday yesterday.
Built by Fletcher Construction, it opened its doors to the public on August 3, 1997.
The tower has gone from a controversial beginning, where many objected to its size dominating the Auckland skyline, to becoming a much-loved symbol and feature of the city.
Initially intended to function as a radio and telecommunications facility, it hosts the world’s largest single FM radio transmitter, as well as television broadcasts, wireless Internet, mobile network, weather measuring and laser link transmissions.
Here are the numbers that illustrate its size and impact on New Zealand:
328
At 328 metres, the Sky Tower is the tallest structure in the Southern Hemisphere. Because of that, it is one of the most-visited tourist attractions in New Zealand. ‘‘SkyCity owns the tower, but really we’re just the custodians of it – it really belongs to the people of Auckland,’’ SkyCity chief executive Michael Ahearne says. By comparison, the Burj Khalifa is the tallest building in the world, at 828 metres. The Sky Tower is eight metres taller than the Eiffel Tower in Paris and 24 metres taller than Sydney’s AMP Tower.
37
The Sky Tower is as tall as 37 buses laid end to end.
2400
Ahearne says the Sky Tower was designed and built with safety in mind and is designed to cope with the elements of nature. The tower is equipped with a fire hydrant system that pumps 2400 litres of water a minute.
200
The base of the tower, which is slightly wider than the shaft, can withstand storms with winds gusting to 200kph.
1
The tower is capable of safely swaying one metre at the top.
90
The steel mast on top of the tower
is 90 metres tall. A gold-plated spiked metal dynosphere, which is 50cm in diameter, sits at its top in case of lightning strikes.
The dynosphere is designed to attract lightning and direct it down a cable and into the foundations where energy is dispersed into the earth.
7.0
The tower was built to withstand a magnitude 7.0 earthquake at 40 kilometres deep or a magnitude 8.5 at 360 kilometres.
1267
The Sky Tower has a total of 1267 stairs leading from the base to its Sky Deck, the highest public observation level.
38
The glass floors on the main observation level are 38mm thick.
85
The tower cost about $85 million to build. Construction took two years and nine months.
15,000
Materials used in the tower’s construction included 15,000 cubic metres of concrete, 2000 tonnes of reinforcing steel, 660 tonnes of structural steel and 260 panes of glass. The empty building weighs 21,000 tonnes – about the weight of 6000 elephants.
18
The lifts travel at about 18kph, or 5 metres per second. Each ride from the bottom to the top of the tower – or vice versa – takes about 40 seconds.